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A. W. BROWNE. 'DENTAL ENGINE HAND PIECE.

Nor-29mm Patented Ja.- 8, 1884.-

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By 711,45' .flttorneys UNrrnn' STATES l PATENT @errent ARTHUR IV. BROVVNE, OF'PL'EASANT PLAINS, N. Y., ASSIGNOR TO THE S. S. VHITE DENTAL MAFACTURING COMPANY, OF PHILADELPHIA., PA.

DENTAL-ENGINE HAND-PIECE.

" SPECIFICATION forming part of Letters Patent No. 291,571, unica January s, iis/i Application med october ai, 1era (No wai-1,)

T @ZZ whom tj/mty concern: l

y Be it known that I, ARTHUR W. BRowNn,

` of the village of Pleasant Plains, in the county of Richmond and State of New York, have in-` vented certain new and useful Improvements in Hand-Pieces for Dental Engines,'ot` which -the following is a specification.

My invention relates to hand-pieces or toolcarriers for dental and other similar engines,

and more particularly to hand-pieces generally known as fchuck7 hand-pieces. The tools, bits, or 'burrs generally used with dental-leni ginehand-pieces are almost if not quite uni A oi" his own manufacture.

versally provided `with round or cylindrical `lock in the new hand-piece. llhe chuck form of hand-piece is intended to receive the shanks of the dental tools without respect'to any peculiar formation ofthe locking-notch therein, so that the hand-piece will drive the tools of one maker as well as those of another.

Several different forms of chuckhan d-pie'ces have already been devised and patented, and some of them possess decided merit; but, as far as I am aware, there had not been produced prior to :my invention a chuck handpeceof simple construction, capable of rapid and easy` operation in locking or disengaging a tool, and one in which the tool would be accnrately centered and firmly locked against all danger of accidental release when in oper` l ation. and in which the steady rotation of the spindle was insured and compensation afforded by rapid and easy adjustment for any wear ofthe parts.

` The object of my invention may be said to h*be to furnish a superior chuck hand-piece meeting all' the requirements demanded in practice of such a device.

,4' The subject-matter claimed is particularly pointed out at theclose of the specification.

A In the accompanying drawings I have shown all of my improvements as embodied in one handapiece in the best way now known to me.

i In said drawings, Figure l is a longitudinal central section through myimprovedhandpiece, showing a tool as inserted therein, `but `not locked in the socket of the rotary spindle which carries it; and Fig. 2 is a similar view, with the parts in position to lock the toolshank in said rotary spindle.

of Fig. 1.

vice. Fig. 5 is a detail view, showing the manner of fitting the drivingshaft to which the power-conveyer is connected in the hollowspindle of the handpiece casing; and Fig. `6 i`s a section on the line 6 6 of Fig. 5. Fig. 7 is a similar section to that of Fig. 2 of a modified form embodying my improvements.

The tubular casing of the hand-piece is composed in this example of ahandle-section, l

A, a union-section, B, a telescoping or sliding section, C, a screw-threaded section, D, and a swivel or shank section, `E, which latter is connected with the usual exible sheath or' covering of the flexible power-conveyer usu ally employed in dental engines. By means of this swivel or shank section the casing of erator. I have not shown in the accompanying drawings said flexible sheath, nor have I l deemed it necessary to show the power-conveyer, usually a iiexible drivingsha-ft, as these instrumentalities constitute no partof my y present improvements, which are confined to the hand-piece of `the engine.

The handle-section A of the casingis united 'l tothe union-section B thereof by being slipped upon the reduced front end of said union-section, and is locked thereon bya set-screw, a, i

having a curved, tapered, or cone end, a', to

act against the inclined wallb of a recess in said union-section. The extent to which the Fig. 3 is a crosssection through the hand-piece on the line 3 3 Fig. i is an end and side'elevation of one section of the clamping or locking de? 180 the hand-piece is free to turn -to conform to the turning movements of the hand of the op i handle-section is slipped endwise `on the union-section is determined by an adjustable j screw. b', fitted in the rear end of the said handlesection of the casing, as clearly shown AI oo in Figs. l, 2, and 7 .A By adjusting thisscrew j b so that its head is extended beyond the rearf end of the handle-section of the casing, said screw abuts against the front face of an annular shoulder, b, of the union-section of the casing, and consequently the extent of projecture of said screw determines the extent to which the handle-section of the casing is passed or slipped upon said union-section thereof. I prefer the face of .said annular shoulder bl of the union-section to have a recess to receive the head or end of the adjusting-screw b', as by this means the proper relation of the two sections is insured, and the fastening-screw a always brought in proper position to act upon the inclined wall of said union-section. It is obvious that by tightening the screw a the tendency is to wedge the handle-section back upon the union-section and lock the two sections firmly together. I do not claim this ad- `iusting-screw and the wedging-screw devices or connections, however, as they are not of my sole invention., and are claimed by me jointly with others in another application.

The union-section B is fitted to receive the front reduced tubular end of the telescoping casing-section C, said telescoping section being provided with a longitudinal groove, c, to receive a spline or feather, f, of the unionsection B. By this construction the unionsection and telescoping sectionv may be freely `telescoped or slid endwise relatively to each other, while, 'when the spline and groove are employed,' they cannot turn independently. This -telescoping construction of the casing sections is important, as will appear hereinafter in the operation of the tool-locking devices.

VA driving-shaft, F, is fitted to revolve on its longitudinal axis in the telescoping section C, and is locked therein, as against endwise movement, by means of a collar, f, fastened on said shaft by a through-pin, f', and embraced between an annular internal shoulder of the telescoping section and the front annular end of the screw-section D of the casing, whereby it will be obvious that as the telescopic section ismoved in and out of the unionsection the shaft F will be moved endwisetherewith. I prefer to fit hardened-steel washers or rings f3 f2, one on each side of said collar f, for accurate iitting, and to withstand the wear to which the parts are subjected. Therear end of said driving-shaft F is connected with the front end of the power-conveyer-usually avflexible shaft-' as before stated. The front end of the driving-shaft F is connected with or carries a rod, G, the shaft and rod being rigidly connected as against torsional strains, while loosely connected as against lateral movement or play, theobject of which connection Will be presently explained. Said rod G is `fitted to move endwise in the rear end of the tubular rotary spindleH ofthe hand-piece, and said rod drives or rotates said rotary spindle H, said v'rod having a feather or lug, g, tting a--longitudinal slot, h, inl the` tubular spindle H, whereby it will be evident that the rod G is free to be mov-ed in and out of the hollow spindle, while any turning movements imparted to said rod G by the driving-shaft F will also be imparted to the spindle H. The rear end of said hollow spindle H terminates in a dat or square annular face, which bears against the front face of a hard-metal washer, i, preferably acting as a facing and guard to'a similar hard-metal washer-or plug, i', tted by screw-threads in the present example in the front end of the union-section B of the casing. By this means the rear end ofthe hollow spinldle may be nicely fitted to bear against the front end of the unionsection of the casing without danger of wear to said section, the wear taking place against the loose washer i above described. When said washer is worn, it may be readily removed and a new one inserted in its place. The front end of the hol` low spindle is cone journaled or tapered to fit a correspondingly-tapered bearing in the front end of the handle-section of thecasing. It will be seen that thetaper given to the front end of the hollow spindle is a double taperthat is, the taper for a portion of its length is at one'angle, while for the remainder of 'its length, at the extreme front end of the spindle, the taper is at a greater angle." This difference of taper, or, rather, the provision of two tapering surfaces on different angles, is for the purpose of resisting side or lateral wear by means of the slightly-tapered surface h', and of preventing the 'iirst taper, hf, from wedging or sticking by means of the taper h2 at a greater angle at the front end of the spindle. It will thus be seen that the spindle is nicely iitted to revolve on its longitudinal axis, and it will also be observed that any wear of the journals of the spindle or of their bearings may b'e readily compensated for by adjusting the handle-section upon the union-section of the casing in the manner before fully described.

In the drawings I have shown the hollow spindle II as having a bearing throughout its entire length in the casing, but in practice lthe spindle will be fitted to turn in front and rear bearings only, with a greater portion of 'its sides removed from contact with the interior of the casing. The rear bearing may be at or near the Vrear end of the spindle, and formed by a hard-metal ring fastened to the inside of the casing, while the front bearing is formed by a hard metal nose of the handle-section fitted with a tapered bore to receive the tapered or cone journaled front end' of the spindle.` The hollow spindle H, it will be noticed, 'is entirely inclosed within the casing, so as to avoid any danger of contact with rotary parts in the manipulation ofthe hand-piece; and this spindle in turnv contains the tool-locking devices by which the tools to be driven and operated may be locked in said rotary spindle, the front end of which constitutes a socketmo receive the shanks of the operating-tools. The bore of the spindle H, at the front end, is tapered or contracted to receive the tapered or con'ed front end of asplit-clamp or spring-jawed locking device. This split clamp or spring-jawed ICO IIO

,Aki

l tion J of the tool-locking device, the front ends V eene-vif e tool-locking deviceis composed in this instancel of' two tubularsections, J J. Thehfrontend,

j, of the front section, J, is tapered to nt the tapered or contracted month of the tool-socket, `and the bore or socket at the rear end of said section is enlarged or flared to receive the front tapered or cone end `of the secondsecof these sectionsJ J being capable of,` being "compressed by being longitudinally slotted for nearly the 'whole length of the sectionsin a well-known way in forming springjawed clamps in thisclass of devices. The rear lend through them to its full extent. f tool-shank of the proper size can now be readof thesection J of the clamp-lock is squareor flat, and the front faceof a headed pin, K, is nicely fitted tofsaid rear end of the section J the shank k of theipin K being fitted in the rear end of' the tool-receiving socket of said `spring-jawed clamp-lock.

lt will beobvious that when no pressure is applied from the `rcaror upon the head of the pin K the tendency` of the springl jaws of the sectional clamp will `be to spread apart and expand, thus opening the tool-receivingsocket A cylindrical ily-inserted in the spindle. Upon applying pressure upon the rearend ofthe spring-clamp lock or upon the"` pin K the front cone end of `the sectionJ of the clamp-lock will be forced infothe tapered mouth of' the front section, J, and the members or jaws of said section J will thus be compressed or forced together, while at the same time the front end of the `section J willbeforced forward and its front spring-jawed end will also be compressed and its members forced together, thereby securely #grasping the tool-shank` at different points, "whilethe clamp-jaw lock will also betightly wedged and locked in the rotary spindle,.so that thetool-shank will be locked to the spindle, so as to be virtually arigid portion thereof.

In order to readily apply the desired pressure to operate or compress the spring-jawed clamp, and fo enable its members fo l expand or release themselves when the pressure is released, `I apply the pressure through the instrumentality of a pivoted bell-crank lever, L,

`and `operate said lever simply by moving the rod G backward and forward, due tomoving the union-section B and telescoping section C of the hand-piece relatively to each other. Said operating-lever L is pivoted by its short arm Z in the spindle, `while the long arm Z of said lever extends lengthwise of the spindle, and is fitted to work laterally relatively to said spindle, and in a longitudinal slot, h3,

thereof'.

The eXtreme end of the long arm Z of the lever Z is bent, "as clearly shown in the drawings, and is adapted to engage a wedge or inclined surface, g, formed on or in the endwise movable rod G, before described. Said wedge or inclined surface g of the rod G is preferably roughened or serrated, as clearly shown, in order to form locking-points forthe engagement of the end of the lever L.

The operation of the device is as follows:

. plained.'

4Willen the parts are in the` position as shown in Fig. l, thetelescoping sections ofthe casing are in their closed position, the rod iG is thrust forward in the spindle, there is no action by i `the wedge or inclinedl surface of said rod upon the lever L, and the spring-jaws of the toolclamp lock are released from pressure, and are' separated, so as to readily receive the shank of a tool. The tool to be used-in operation is now inserted. The handle-section of the casing is now grasped in one hand and the telescoping section C in the other, and the `two `separated or pulled apart, as shown in Fig. 2. This separation of the section C from the sections A and B carries the spindle forward,and causes the end of the long arm of the lever L to ride upon the wedging or in-` clined surface of the rod G, which action, as will be obvious from Fig. 2, causes the elbow of the leverL-at the point l, for instance-` to bear against the head of the pin K and force spring-clamp locking device, whose ends 0r `it forward, carrying with it, of course, the V jaws are thereby contracted or compressed upon the tool-shank in the manner before exwork, and will be rmly, steadily, an-d securely driven without any danger whatever of the release ofthe tool, as the force of compression The tool may now be directed to its exerted by the spring-jaws, due to the action-r of' the lever L, is comparatively great, and

much more efficient than any previous toollocking device of its kind as far as Iamaware.

The lever L will be securely held in its locking position 4by the engagement of its end with `one of the teef-hor sei-rations in the wedging, .camming, or inclined surface of the rod G. All that is necessary, therefore, it will be ob-`A vious, to lock or release atool, isto moveone section of the casing endwise upon the other.; The movement may be accomplished instantly,

and is easily accomplished without the eXe"r`-`v cise of much exertion. .i

For `the purpose of' adjustment andv to lsecure accurate fitting, `l prefer tointerpose between i Instead ofl a sectional or two-part springclamp, it may be formed in one piece-for instance, having spring-jaws at its opposite ends beveled or tapered and adapted to be compressed at one end by a proper surface in the spindle, and at the other end by a tapered mouth or recess in the end of an endwise movable rod against which the elbow-lever may operate, which is a common construction (ex-n cept, of course, the lever) inthis class of handpieces. Other chan-ges, of course, may be made without departing from my invention.

I do not deem it necessary, however, to recite in detail all the changes that might be made, as many of them will be obvious to constructors of dent-al machinery and tools of a kindred nature. In Fig. 7 however, I have shown a modification, in which the casingsections, when `closed or brought together, operate the elbow-lever by means ot' a wedging or camining surface instead of operating the lever to lock a tool in the spindle by separating said sections, as in the example iirst described.

Without elaborating the simplicity and effectiveness of my improved hand-piece, its durability, or its capacity for taking npl or compensating for wear, or its case and rapidity of operation, I will state that I claim herein as of my inventionl. vIn combination with the casing of a dental-engine hand-piece, a spindle fitted to rotate in said casing having a journal tapered at different angles, substantially as described. 2. The combination of aspindle fitted to rotate in a hand-piece casing, a tool-locking de- `vice carried by said spindle, and connections between said tool-locking device and telescoping sections of said casing, substantially as described.

3. The combination of a spindle fitted to rotate in bearings, an endwise-movable toollocking clamp carried by said spindle, and a rocking lever to operate said tool-locking clamp, substantially as described.

4. The combination of a spindle fitted to ro- 6. The combination of the tool-lockoperat ing` lever with the wedge or incline to operate saidlever, having a notched or serrated surface, substantially as described.

7. The sectional split clamp tool-locking 5o device, consisting of front section having an externally-tapered or coned front end, and an 4internally-tapered mouth or socket at the opposite end, with a rear section having its front end coned or tapered to tit the coned mouth 55 or socket of said front section, substantially as described.

S. In co1nbination,with an endwise-movable clamp-locking device, a headed pin, fitted by its shank in said device and adapted to receive 6o the pressure .which closes the jaws of the clamplock, substantially as described.

9. The combination ofaspindle fitted to rotate in bearings in a casing, but locked from independent endwise movement therein,a tool- 6 locking device carried by said spindle, a driving-shaft also fitted to rotate in said easing and locked from independent endwise movement therein, a telescoping connection between the respective sections. of said casingin which the 70 spindle and shaft are mounted, and a connection between said shaft and said tool-locking device, whereby the reciproeation or telescoping of the easing-sections operate said toollock, substantially asdescribed. 7 5

as described, whereby the casing-sections may so be tclescoped in a right line, but cannot turn y v relatively to each other.

In testimony whereof I have hereunto sub'- scribed my naine this 24th day of September, l ,y

` ARTHUR W. BROVNE.'

\Vitnesses: (Ei-ms. THR-ALL, G. GULowsEN. 

